Species distribution over part of the Coonalpyn Downs, South Australia

1956 ◽  
Vol 4 (1) ◽  
pp. 68 ◽  
Author(s):  
WH Litchfield
Keyword(s):  
Water Relations ◽  
Species Distribution ◽  
Sand Dunes ◽  
South Australia ◽  
Plant Distribution ◽  
Poor Correlation ◽  
Soil Reaction ◽  
Rainfall Gradient ◽  
Profile Characteristics ◽  
Sclerophyllous Vegetation

An account is given of edapho-climatic ranges and species area of elements of the mainly sclerophyllous vegetation of a representative portion of the Coonalpyn Downs. Eucalyptus, Melaleuca, Acacia, Hakea, Leptospermum, Casuarina, and Callitris are the principal genera discussed. Water relations as governed by soil profile characteristics, landscape position, and the depth and salinity of water-tables are considered to be the main factors influencing plant distribution. The rainfall gradient across the area is gentle and rainfall as an independent factor only appears to influence water relations sufficiently to affect species distribution in a few cases. The fertility of soils on sandplain and sand dunes is invariably of a low order and a species composition typical of higher fertility soils is usually only found on inliers of such soils. Subsidiary edaphic responses include gross changes in soil reaction and soil salinity. A few indicator species in a given plant community can be associated with some particular soil characteristic and such correlations are distinct from community responses. For example, Hakea vittata in heath is generally associated with sandplain soils with a lime pan or a calcic subsoil within 2 ft of the surface. An examination of the area of numerous species shows that there is considerable variation across the territory in the composition of communities with repetitive dominants. Evidence is presented that suggests that species migrations may have spread from refuges or at least continuously vegetated areas within the territory as well as from outside it. The poor correlation between the area or limits of centres of frequency of some species and their observed edapho-climatic ranges suggests that migration is still occurring and that the climax community has not been produced in all cases.

Population Dynamics and Movement Patterns of Bolam's Mouse, Pseudomys bolami, at Roxby Downs, South Australia.

1998 ◽  
Vol 20 (3) ◽  
pp. 353
Author(s):  
K.E. Moseby ◽  
J.L. Read
Keyword(s):  
Arid Zone ◽  
Sand Dunes ◽  
South Australia ◽  
Breeding Strategy ◽  
Early Summer ◽  
Ecological Data ◽  
Winter Rainfall ◽  
Land Systems ◽  
Single Night ◽  
Time Of Year

Basic ecological data were collected on Bolam's mouse, Pseudomys bolami, during a six year trapping study at Roxby Downs in northern South Australia. Pseudomys bolami inhabited mixed arid land systems in the Roxby Downs area, sheltering in the longitudinal orange sand dunes but foraging at night principally on the adjacent chenopod swales. Distances of up to 334m were traversed in a single night and recapture rates were high within trapping sessions but low between sessions suggesting wide-ranging movements and short-term residency. Dietary observations imply an omnivorous diet. Whilst the closely related P. hermannsburgensis is regarded as having an opportunistic breeding strategy, P. bolami reproduced opportunistically but also regularly in spring and early summer. Different reproductive strategies may be influenced by the latitudinal distribution of P. bolami near the southern margin of the arid-zone, where rainfall can occur at any time of year but winter rainfall is more predictable. This contrasts with P. hermannsburgensis, which inhabits more northerly arid areas where rainfall is erratic and unpredictable. There was a 10 fold fluctuation in P. bolami captures over the trapping period with numbers of P. bolami and house mice, Mus domesticus peaking 12 months after above average rains during 1992. Rodent captures remained high for two years afterwards. Although P. bolami persisted throughout the study period, M. domesticus was only present when conditions were above average. Trap success of P. bolami or M. domesticus did not vary between the five sub habitats at the 1 ha study site. However, trap success of P. bolami was positively related to vegetation cover, particularly cover of low bluebush, Maireana astrotricha. Maireana astrotricha may be important in providing both food and cover for P. bolami, a scenario consistent with the utilisation of spinifex, Triodia spp. by P. hermannsburgensis in the northern arid-zone. Past over- grazing of chenopod shrublands may have reduced cover and contributed to the suggested decline in the distribution of P. bolami.

Leaf tissue water relations and hydraulic properties of sclerophyllous vegetation on white sands of the upper Rio Negro in the Amazon region

2009 ◽  
Vol 25 (3) ◽  
pp. 271-280 ◽  
Author(s):  
M. A. Sobrado
Keyword(s):  
Water Relations ◽  
Specific Conductivity ◽  
Leaf Tissue ◽  
Amazon Region ◽  
Tissue Water ◽  
Xylem Structure ◽  
Sclerophyllous Vegetation ◽  
And Function ◽  
White Sands ◽  
Leaf Survival

Abstract:The objective of this study was to explore the leaf tissue water relations in terminal branches, as well as the relations between xylem structure and function of five sclerophyllous species coexisting on white sands within the Amazon region. In these species, which possess costly leaves and thrive in an extremely nutrient-poor habitat, the preservation of leaf survival would be of comparable importance to the preservation of xylem vessels. Three trees per species were tagged in the field for all measurements. Minimum leaf water potential (Ψ) was −1.53 ± 0.61 and −0.94 ± 0.10 MPa during rainless and rainy days, respectively. The Ψ for turgor loss averaged −1.92 ± 0.05 MPa. Therefore, minimum Ψ was maintained within a safety range above the critical value for turgor loss. Xylem (Kx) and leaf (Kl) specific conductivity averaged 1.4 ± 0.22 and 0.00033 ± 0.000045 kg m−1 s−1 MPa−1, respectively. Water supply was favoured in species with higher vessel density, and all species depended on relatively less abundant larger vessels for water transport. This would be advantageous because leaves were unable to develop very negative water potentials in order to maintain transpiration. High transpiration rates may be restricted to a few hours daily so as to prevent cavitation of widest vessels.

Water relations of feral olive trees (Olea europaea) resprouting after severe pruning

2000 ◽  
Vol 48 (5) ◽  
pp. 639 ◽  
Author(s):  
Megan Shelden ◽  
Russell Sinclair
Keyword(s):  
Water Relations ◽  
Olea Europaea ◽  
South Australia ◽  
Plant Water ◽  
Soil Matric Potential ◽  
Matric Potential ◽  
Water Potentials ◽  
Olive Trees ◽  
Autumn And Winter ◽  
Olea Europaéa

Water relations of feral olives (Olea europaea L.) were studied on a location in the Mt Lofty Ranges, South Australia. In spring (October–November), 6 months before the study commenced, an area of trees had been cut back to stumps as part of an eradication project. The stumps resprouted vigorously over summer, similarly to regrowth seen following wildfire. The following autumn and winter, plant water potentials and soil matric potentials were measured on the cut trees and adjacent control trees, to determine whether the cut trees were better hydrated due to the pruning treatment. In autumn, before the winter rains began, the resprouting trees were more hydrated than the control trees, with a difference in predawn water potentials of between 2 and 4 MPa, and 1.5 MPa or greater throughout the day. The soil matric potential was much less negative on the cleared site, both at the surface and at 50-cm depth, indicating that soil water had been less depleted by the cut trees than by the intact trees. This improved hydration was similar to that reported for sclerophyll vegetation after defoliation by fire. Results have some significance for feral olive eradication projects.

Inferring the impact of rainfall gradient on biocrusts’ developmental stage and thus on soil physical structures in sand dunes

2014 ◽  
Vol 13 ◽  
pp. 81-89 ◽  
Author(s):  
Eli Zaady ◽  
Itzhak Katra ◽  
Hezi Yizhaq ◽  
Shai Kinast ◽  
Yosef Ashkenazy
Keyword(s):  
Developmental Stage ◽  
Sand Dunes ◽  
Rainfall Gradient ◽  
The Impact

scholarly journals Jumping the barrier: Does a glacier tongue affect species distribution along the elevation gradient in the subnival and nival belts? A case study on Mt. Kazbegi, Georgia, Central Great Caucasus Mountains

2020 ◽  
Vol 44 (2) ◽  
pp. 219-229
Author(s):  
Zaal Kikvidze ◽  
Tamar Jolokhava ◽  
Arsen Bakhia ◽  
Otar Abdaladze
Keyword(s):  
Species Distribution ◽  
Vegetation Structure ◽  
Elevation Gradient ◽  
Plant Distribution ◽  
Usual Sense ◽  
Rapid Decline ◽  
Plant Abundance ◽  
Glacier Tongue ◽  
Vegetation Patches

Glaciers are a prominent feature in high mountains and can affect plant distribution along the gradients. However, the possible effect of glaciers on plant community structure at landscape scale has been little studied. We asked: if a glacier tongue crosses a slope laterally and potentially blocks dispersal and migrations, how can this affect vegetation structure and species composition below and above this barrier? A suitable study system is offered by slopes on Mt. Kazbegi, where we established a transect through the subnival and nival belts. We sampled vegetation below and above the glacier tongue and conducted direct gradient analyses to reveal possible effects of the glacier on patterns of species distribution and vegetation structure such as the ratio of solitary plants in vegetation patches. The obtained results indicate that the glacier tongue in our study does not cause a ?vegetation switch? in the usual sense of this phrase. However, it might contribute to an abrupt change in the share of solitary plants, as well as to a very rapid decline of plant abundance and species numbers above the glacier.

Dark Island heath (Ninety-mile Plain, South Australia). II. The effects of microtopography on climate, soils, and vegetation

1957 ◽  
Vol 5 (1) ◽  
pp. 86 ◽  
Author(s):  
P Rayson
Keyword(s):  
Sand Dunes ◽  
South Australia ◽  
Vegetation Pattern ◽  
Growth Conditions ◽  
Individual Growth ◽  
Homogeneous Groups ◽  
Vegetation Communities ◽  
Representative Species ◽  
Westerly Winds ◽  
The Individual

The topography of the experimental area at Dark Island is described as a series of crescentic sand dunes formed under the influence of westerly winds and separated by undulating sandplain. Variation in the heath vegetation of the area in relation to topography was described by means of the varying densities of 12 representative species. These densities indicated the individual growth tolerances of the vegetation components. One hundred and twenty-six quadrats sampled from different topographical positions were sorted into homogeneous groups by the method of positive interspecific correlation. The four resultant vegetation communities were located respectively on eastern dune slopes, western dune slopes, sandplain, and in scattered sites. Examination of soil texture, rainfall incidence, and average daily hours of direct sunlight in relation to topography showed that three microhabitats can be separated: namely, eastern and western dune slopes and the sandplain. Eastern dune slopes have the most favourable growth conditions, western the least favourable. Neither the vegetation communities nor the microhabitats could be sharply delimited. The gradual changes of soil and microclimate produced a varying but continuous vegetation pattern. This pattern depended on the growth tolerances of different species and probably also on interspecific competition for the more favourable growth sites.

Reliance of creek-side river red gums on creek water

1994 ◽  
Vol 45 (8) ◽  
pp. 1439 ◽  
Author(s):  
PJ Thorburn ◽  
LJ Mensforth ◽  
GR Walker
Keyword(s):  
Stable Isotopes ◽  
Soil Water ◽  
Water Relations ◽  
South Australia ◽  
Eucalyptus Camaldulensis ◽  
Saline Groundwater ◽  
Naturally Occurring ◽  
Creek Water ◽  
Eucalyptus Camaldulensis Dehnh ◽  
Semi Arid

Measurements of naturally occurring stable isotopes of hydrogen (2H) and oxygen (18O) were used to determine the importance of creek waters to river red gums (Eucalyptus camaldulensis Dehnh., Myrtaceae) on the banks of creeks in the semi-arid and saline Chowilla floodplain region of South Australia. The 2H and 18O concentrations of water sampled from trees were significantly different from those of the creek water, indicating that, generally, trees were not obtaining all their water from the creek. This was found even in trees overlying highly saline groundwater. Thus, saline groundwater and/or soil water were important water sources for the trees studied. The results indicated that the water relations of these trees are complex, and the trees may be less affected by changes in creek flow and/or salinity than was previously anticipated.

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